Finite Element Method Of Adhesives Structure On Composite Wing

For all- composite wing, the use of mechanical connections would increase the weight of the system but not fully loss ing weight results. For adhesive connections caused no drilling stress concentration, and having no effect on the lap board’s stiffness and strength; small number of parts, light structure, good ligat ion efficiency, reducing the cost of parts; being able to obtain a smooth aerodynamic advantages. However, adhesives had the fo llow ing disadvantages: large dispersion force, being difficult to equal strength design, subjecting to environmental impact, process demanding, layer thickness have a greater imp act on the layer of stress, bonding structure can not be demolished. Without taking into account the process on the basis of an all- composite wing design layer ha d the following two difficult ies:(1) determine the adhesive thickness, For changes in layer thickness have a greater impact on the adhesive of stress;(2) Composites equal design of parts and ahesive, because the composite parts and adhesives had different strengt h criteria. When performing finite ele ment analys is, the main difficult y was the geometry of the model ahesives and composite parts having five orders of magnitude difference it caused that calculation time was very slow.In response to these questions, the paper first studied the mechanical properties of the composite single lap in the lap plate layer being deformed by the load under three different loading, and studied the strengt h criterion layer and composite overlapping plates research. Then by studing the finite element method of two- and three-dimensiona l models obtained the effects of stress and three-dimens ional effect on adhesive interface portion and the middle layer to layer, and studied the lap lengt h, layer thickness and overlapping forms of influence on layer stress. Test and pulled off by stretching experiments were determined layer shear strength and pull-off strengt h. Final design of a long all- composite wing aspect ratio was using C ATIA composite ply design, through the flight environment has been surface loads, use ing Hypermesh performed before treatment, importing C AD model to C AE software processing for model. There are too many finite ele ment in meshing, using the sub- model method of processing, greatly reducing the number of elment. Fina lly, the preferred method of using the program to analyze the influence of various paramete rs on the stress layer by orthogonal experiment, so that the strength of the composite structure and the adhesive meeted the bases, to achieve the lightest weight.